Monday, January 31, 2011

Temperatures tumbled Monday morning across the Charlotte region, ushering in a week of wild weather for the area.

It means an end to the beautiful conditions we enjoyed over the weekend, but don't complain. We're getting off easy.

Another in a seemingly endless series of powerful winter storms is predicted to form over the Southwest, then move east-northeast across the country and pummel most of the nation's major cities with some type of nasty winter weather.

Believe it or not, 28 states have winter storm watches or warnings in advance of the storm. If that's not bad enough, the storm system could trigger severe thunderstorms over the Deep South.

And following the storm is a surge of very cold air, producing the coldest temperatures in decades for some areas.

First, let's look at our upcoming week of strange weather.

A cold front slipped southward overnight, dropping temperatures from 51 degrees at midnight (that will be our high for the day) to 39 at 7 a.m. It might not get much warmer today, as cold air flows off the Atlantic from a high pressure system over New England.

That means temperatures today will be about 30 degrees colder than Sunday's high of 71 in Charlotte -- which was the warmest reading since Nov. 23, when it reached 73.

We'll be locked in a cold air damming situation, with damp and chilly air coming off the Atlantic and dammed against the mountains. By midday Tuesday, the big storm system will have formed to our west and will be moving eastward. It will erode the cold air damming later in the day, and rain will arrive by nightfall.

Wednesday could be a strange day. Rain will end in the morning, followed by sunshine, much warmer temperatures, and the possibility of very windy conditions. Highs will shoot back up into the middle 60s Wednesday afternoon, and we'll have to watch for the chance of strong wind gusts.

Then cold air will pour back into the area Wednesday night, and our highs Thursday will plummet back into the upper 40s.

If all that isn't enough, a low pressure system is predicted to track along the Gulf Coast late Thursday or early Friday. National Weather Service forecasters say some light sleet, snow or freezing rain could spread into northern South Carolina and possibly as far north as the Charlotte area -- but no accumulations are expected.

The big storm this week, however, will be elsewhere in the nation. If you're traveling this week or have family elsewhere in the country, here's a look at what is predicted for some of the major metropolitan areas:

Dallas: Not a good situation for people gathering in advance of the Super Bowl. Cold air pours into the region late Tuesday, and temperatures are not expected to get above freezing -- above freezing!! -- from late Tuesday until sometime Friday. To make matters worse, there's a chance of sleet and freezing rain Wednesday. This week's temperatures will be the coldest in about 20 years for Dallas.

St. Louis: Heavy snow and enough ice to cause problems.

Chicago and Milwaukee: A blizzard watch has been posted, with up to 2 feet of snow in the downtown area from late Tuesday through Wednesday.

Detroit: About a foot of snow from late Tuesday into Wednesday.

Cleveland: Several inches of snow tonight, caused by a warm front forming ahead of the storm. Then several more inches late Tuesday and Wednesday, with damaging ice accumulations, too.

Cincinnati: On the edge of an ice storm. The city might be far enough south to miss the worst of it.

Pittsburgh: An ice storm looms for Wednesday.

Buffalo: About 1 1/2 feet of snow Wednesday.

Philadelphia: Some ice accumulations, but it's too early to tell if it will be enough to cause power outages.

New York City: Heavy snow and ice Wednesday.

Boston: From 6 to 12 inches of snow late Wednesday, and possible ice problems.

Baltimore and Washington: A major ice storm is possible for Baltimore, but Washington might escape with non-damaging amounts of ice. Farther inland in Maryland, near Frederick, there could be very heavy ice accumulations.

Escaping the worst of it: Houston, New Orleans, Memphis, Atlanta, Charlotte and points south. Also, cities farther to the north, such as Minneapolis, will not be affected.

Friday, January 28, 2011

Weather won't make headlines this weekend in the Carolinas and elsewhere in the South.

After weeks and weeks of snow, sleet and relentless below-average temperatures, we're moving into a four-day period of really pleasant weather, considering it's still January.

Enjoy it. We've earned the fair weather and temperatures in the mid to upper 50s.

Next week looks like a different story.

All the computer models predict a strong storm system will form over the Southwest early next week and then move eastward and curve northeast. Initially, the storm was predicted to follow a southerly track, putting the western Carolinas on the cold side of the precipitation.

But the models have shifted the storm track, and nearly all meteorologists now expect the storm's center to pass well west of the Carolinas on Tuesday and Wednesday. That will put us on the east-southeast, or "warm," side of the storm.

We need the precipitation, as Charlotte is about 6 inches below average since the beginning of October. We don't need severe weather, though, and that's always a problem for areas on the southeast side of strong low pressure systems. We'll keep an eye on that possibility early next week.

And as the storm system swings northeast, heading up into the Great Lakes and then into Canada, it is forecast to drag very cold air into the United States later next week. For now, the computer models predict the worst of the cold air will filter southward from the upper Midwest into Oklahoma and Arkansas, possibly reaching the northern half of Texas.

Some moderation in the arctic blast is forecast for the Southeast.

What does all this mean, in daily forecast terms?

Through Monday ... Very nice conditions, with sunny to partly cloudy skies, and temperatures at or above average for this time of year.

Tuesday and Wednesday ... A rainy period, with the chance of thunderstorms somewhere in the Carolinas.

Thursday into next weekend ... A return to colder weather, but we don't know exactly how cold yet.

Thursday, January 27, 2011

We're about to enjoy our first stretch of tolerable weather since Thanksgiving, and that's a good time to note we've reached a major landmark in what has been a nasty winter.

It's a small landmark, with mostly symbolic meaning, but we'll take anything we can get this winter.

On Monday, the average high temperature for Charlotte was 52 degrees. That's notable because it was an increase of 1 degree from the previous day.

Monday marked the day when -- based on climate history in Charlotte -- the weather begins to warm. The path to summer begins slowly, but it's a start. Next Monday, our average high climbs to 53 degrees. By the end of February, it's 58.

Some people assume the temperature turnaround begins Dec. 21, the first official day of winter. But the atmosphere has a built-in delay process, and our coldest weather usually comes about a month after winter starts. It's the same for summer, with the hottest temperatures, on average, in mid-July.

You also should be noticing a change in the amount of daylight. It should be especially noticeable over the next few days, when we have sunny conditions in Charlotte.

Sunset is about 40 minutes later now than in mid-December, and the total amount of daylight at the end of January is 37 minutes longer than at the start of the month. We add nearly another hour of daylight in February.

This certainly doesn't mean winter is over, even though we'll be enjoying temperatures near 60 degrees this weekend. Some meteorologists and weather geeks were writing on weather bulletin boards last week about a possible monster storm arriving this weekend, but that didn't develop. Instead, we might experience our first stretch of three consecutive days with above-average high temperatures this winter.

Looking down the road ... an arctic air mass is predicted to move into the Midwest and reach as far south as Texas next Tuesday, and at least some of that cold air will spread eastward later in the week.

But that seems far away right now.

The sun is out, average temperatures are climbing, the amount of daylight is growing, and for at least a few days, we can forget about the worst of winter (provided we're not trying to catch a flight to the snow-beleaguered East Coast).

Saturday, January 22, 2011

Today's lesson ... how a predicted snowstorm can turn into a rainstorm, in just 12 hours.

That's what happened Saturday, as the computer models began moving slightly toward something resembling consensus about a storm system expected to affect the Charlotte region late Tuesday and Wednesday.

A few days ago, the computers were predicting a heavy snowfall Monday. Now, the arrival of precipitation has been pushed back to later Tuesday, and at least some meteorologists are thinking the storm might bring nothing worse than a cold rain to the immediate Charlotte area.

Bryan McAvoy, of the National Weather Service office in Greer, S.C., said Saturday afternoon that it's still too early to predict where the rain-snow line will be. But he says it appears as if the mountains and adjacent foothills could get heavy snow, with a few inches falling in a corridor from Greenville, S.C., to Statesville. That would include places like Shelby and Hickory.

He also says "the idea of a rain-snow event looks better than ever."

Translated: We won't have to worry about sleet or freezing rain this time. A glaze of ice turned the Jan. 10 snow in Charlotte into a dangerous mess.

Earlier Saturday, forecasters said the computer models were indicating Tuesday's storm could be much like the Christmas day event, in which precipitation started as rain in Charlotte but changed to snow, leaving a couple inches on the ground -- with heavier amounts along the Interstate 40 corridor.

But it looks increasingly as if warmer air will be a part of the storm system -- and, hence, the idea that rain, not snow, will fall in Charlotte.

Anyone in the Charlotte region who dislikes winter weather must feel besieged today, with snow and cold weather seemingly attacking from all directions.

After all, snow is expected to fall this afternoon in Charleston, and bitterly cold arctic air is pouring into the region from the northwest.

The big news for the area continues to be the possibility of a snowstorm Tuesday into early Wednesday, but there is more on the plate this next-to-last Saturday in January.

We still don't have a firm grasp on exactly what will unfold with the next winter storm expected for the Carolinas. The general thinking hasn't changed ... low pressure will form in the Gulf of Mexico on Monday and then move across the Southeast.

That low pressure will intensify and take a run up the East Coast, bringing absolutely awful weather to the big metropolitan areas that already have been clobbered several times this season.

But what about the Charlotte area?

Blair Holloway, of the National Weather Service office in Greer, S.C., said Saturday morning the current guess is Charlotte will get rain to start Tuesday, but precipitation will change over to snow. Areas to the north and west of Charlotte would get mostly snow.

This might sound familiar, Holloway notes. "This would be similar to the Christmas day storm," he says.

Meanwhile, Accu-Weather is predicting some rain and some freezing rain for Charlotte, with heavier snow reserved for the foothills and mountains. One of the key computer models for weather forecasting, the GFS (Global), predicted Saturday morning that the storm would take a rather northerly track, bringing more warm air into the Charlotte region.

The other models have colder predictions ... and, hence, more snow.

Here's something else to ponder. Some of the models are hinting at a major storm next weekend. I haven't been paying very close attention to that, but my brother Michael -- who is very weather-savvy -- mentioned to me this morning that some weather professionals have been comparing overall conditions next weekend to March 1993 (the Superstorm).

In the meantime, let's look at the two current pieces of the winter picture:

Snow in Charleston? Low pressure formed off the Florida coast Saturday morning, spreading frozen precipitation onto parts of the coast. Light sleet and snow fell near Charleston, but more significant snow fell Saturday afternoon near Wilmington.

Up to an inch could accumulate in such unlikely places as Ocean Isle Beach and Wrightsville Beach this afternoon, before the storm system moves out to sea.

Cold air. Actually, the Carolinas were spared the worst of the nasty cold blast the past few days. Low temperatures Saturday morning in the mountains were in the mid teens, but the coldest air remained north of the region.

Readings were as cold as 11 degrees below zero in Zanesville, Ohio, not far from Columbus, and the thermometer fell to 1 degree at Lexington, Ky.

High pressure responsible for those cold temperatures will move over New England early in the week and pump chilly air into the Carolinas. That will set the stage for our winter storm Tuesday.

Friday, January 21, 2011

The emerging trends about the winter storm expected to impact the Charlotte region next week are that it will be big, and that it will produce a mix of precipitation.

As is typically the case, if you check with five meteorologists, you'll get five different forecasts. I'll try to touch on all those possibilities here.

We know the storm will form along the southern jet stream, over the Southwest or in the Gulf of Mexico, and move toward the Southeast. Another weaker storm system will dive southward from the Midwest along a northern jet stream, and the two will phase somewhere in the Southeast.

The result will be a pretty strong storm, which is expected to move up the East Coast and bring more misery to places like Philadelphia, New York City and Boston -- where this winter already has been plenty miserable.

Then again, our winter has been miserable in its own right. Next week's storm will add to that.

Brad Panovich, the chief meteorologist at our news partner WCNC-TV in Charlotte, mentioned that the storm could dump heavy snow somewhere in the western Carolinas. And with strong winds expected with the storm, conditions could seem almost like a blizzard.

Frank Strait, a meteorologist with Pennsylvania-based Accu-Weather, said early Friday morning that the computer models he examined pointed to more of a wet event for Charlotte -- rather than frozen precipitation. He doesn't expect the storm to reach maturation until after it passes the Piedmont area and begins moving up the coast.

"In the Piedmont ... it would start as snow, then go to ice, and to rain," said Strait, who, incidentally, is from Rock Hill and plans to drive down here Wednesday -- if the roads are passable.

As Strait noted, if the storm's center tracks a bit farther east than the models predicted, then slightly colder air could filter into the Charlotte area, and more of the precipitation would be snow, rather than rain.

Another meteorologist, Mike Dross, says the models indicate precipitation starting as snow, then changing to sleet or freezing rain east of Interstate 85. Dross, now based in Houston but formerly of Charlotte, says the storm could be "a blockbuster."

We'll keep watching the evolution of this storm system over the weekend.

The chances of a winter storm across the Carolinas early next week remain strong, and, in fact, they grew stronger overnight.

The computer models all seem to be coming aboard with the idea of a low pressure system forming in the Gulf of Mexico and phasing with some upper-level energy spinning southward across Tennessee.

Some of the models predict this will become a strong storm, although the consensus seems to be that the heaviest wintry precipitation would fall farther up the East Coast -- from, say, Virginia northward.

That's because the storm wouldn't have organized fully when it is affecting the Carolinas.

All of that is subject to change, of course.

One thing already has changed -- the timing.

Yesterday, we were talking about a Monday arrival. Now it looks as if the precipitation won't start until sometime Tuesday, and it might last into early Wednesday.

And the best thinking from meteorologists now is that the Charlotte area would get snow at the start, changing to sleet, then to freezing rain, and finally to rain. Of course, we don't know yet whether it'll be mostly snow, or mixed precipitation, or rain. But the advance forecast is for temperatures to climb above freezing in the immediate Charlotte region during the storm.

This is a quick post, and I'll write something more detailed later today.

Thursday, January 20, 2011

The last of the Jan. 10 snow and ice has melted finally, and now the weather computer models are predicting another bout of frozen precipitation early next week.

The various computer-generated forecasts used by meteorologists to predict the weather were pretty much in agreement leading up to the Jan. 10 storm, but that's not the case this time.

The next system falls pretty much in line with the typical Southern winter storm -- difficult to predict in advance.

The system is expected to form in the Gulf of Mexico this weekend and cross the Southeast, in some fashion, either Monday or Tuesday. Meanwhile, high pressure will build over New England, pumping cold air into the Carolinas.

And as all of you who have spent one or more winters in the Carolinas know, a Gulf storm and a New England high are the ingredients for problems.

But get a load of these varying predictions for the system:

GFS (Global) model ... It calls for a quick-hitting storm, with precipitation arriving Monday afternoon and leaving by early Tuesday morning. That would mean not a lot of precipitation, but the Global model sees most of it falling as snow, sleet and freezing rain.

ECMWF (European) model ... This forecast keeps the storm system pretty far off the Carolinas coast and predicts the New England high won't be quite as strong as some other forecasts. That means much of the precipitation would remain south and east of Charlotte, and temperatures might warm enough for rain to be a part of the mix.

GEM (Canadian)model ... This model predicts a longer-lasting storm, with precipitation falling into Tuesday, and with plenty of cold air.

All three models show some amount of snow, sleet or freezing rain for the Charlotte area, but there are big differences in how much falls, and when.

Tuesday, January 18, 2011

A friend of mine advised me on Sunday that we'll be getting more snow, in about 10 days.

Penny doesn't pay attention to the computer models or any other long-range forecasting tool. She based her forecast on folk legend.

I've learned there's no shortage of folk legends, especially when it comes to snow in the South.

Penny's forecast of snow later next week is based on the weather proverb that says, "If it rains with snow on the ground, more snow is coming." We still had plenty of patches of snow and ice on the ground Monday night when the rain started falling. So I guess that means we'll have another round of wintry precipitation in about 10 days.

Maybe the strangest proverbs I've heard came from a student in the Sunday school class I teach. My daughter and I have a group of 18 extremely bright eighth-graders, and after class on the night of Jan. 9 (a week ago Sunday), I started talking to a seventh-grader from another class.

Cassie Rowell informed me that students believe they'll get a snow day if they wear their pajamas inside out at night, or if they leave a spoon under their pillows. She planned to do both that night.

There are many others, of course.

Probably the most famous is Groundhog Day. If the groundhog sees its shadow on Feb. 2, it means six more weeks of winter. We'll examine that issue on Groundhog Day, but suffice to say the theory doesn't hold up very well under scientific study.

When I moved to the South more than three decades ago, I was told that thunder in winter was followed by snow, 10 days later. There's a bit of support for that, since thunder in the winter usually accompanies strong cold fronts, and if really cold air is pouring in, it sets the stage for a winter storm. But I looked at four cases in recent years, and none of them panned out.

Another one ... the number of August fogs equals the number of snowfalls in winter. National Weather Service records show one significant fog event in August for Charlotte, and snow already has fallen twice (three times, if you count the snow-sleet event of Dec. 16). so forget that one.

An interesting tale I heard recently was that thunder in February means frost in April -- on the same date. In other words, if there's a thunderstorm on Feb. 10, there'll be frost on April 10. I'll have to watch for that.

One saying that makes plenty of sense is "A year of snow, a year of plenty." A lot of snow in the winter means groundwater supplies will be replenished when the snow melts. And that puts the soil in good shape for spring planting.

Personally, I'll stick with the Global, European and Canadian computer models. I've got nothing against the wisdom of those who came before me, but science seems a bit better-grounded.

Then again, Cassie Rowell's inside-out-pajamas and spoon-under-the-pillow trick worked. We got 4 inches of snow on Jan. 10, and she was out of school for several days.

Monday, January 17, 2011

After getting clobbered with arctic air masses and winter storms the past month, the Charlotte region will miss the worst of what's coming in the next five to seven days -- apparently.

A storm system is tracking eastward today, delivering a belt of snow and freezing rain.

Since mid-December, the storm track frequently has been across the Southeast, with the Charlotte area on the north (cold) side of the system. The result: sleet on Dec. 17; snow on Dec. 25 and 26; and then snow, sleet and freezing rain last Monday.

This time, the storm's path is north of our area. That puts us on the milder side of the system, and it means any precipitation that falls today and Tuesday will be in the form of rain -- except perhaps in the higher mountain altitudes.

Instead, it looks like freezing rain could be a problem in places like Washington, Baltimore, Philadelphia and maybe the New York City area.

Then there's the matter of the next arctic blast, headed for the continental United States this weekend.

Originally, the computer models indicated the very cold air would push well into Georgia and South Carolina, much like the air masses have done in recent weeks. That would mean another round of far-below-average temperatures from Saturday into the early part of next week.

But now it looks as if the cold air will sweep over the Upper Midwest, Great Lakes and Northeast. In the Carolinas, we'll be at the edge of the cold air mass. Our temperatures will turn chillier again this weekend, with highs in the low 40s. But we won't be looking at a string of days with 35-degree highs --hopefully.

Some of the advance forecasts show a trend of near-average temperatures for the next 10 days or so.

Given the history of this winter, I doubt that. There's still too much cold air in place over Alaska and Canada. But we'll take every day of "average" we can get.

Thursday, January 13, 2011

I spent more than a few sentences in late autumn describing what a mild and dry winter we would have in the Carolinas.

Talk about making a mistake!

Most long-range meteorologists predicted the Southeast would slide through winter with few if any problems. Those forecasts were based on the emergence of La Nina, the Pacific Ocean condition that tends to keep the South mild in winter while sending the nasty weather into the Northwest.

I remember seeing a comment posted under one of my blog entries from someone who took exception with the forecast, saying there are other conditions at work, including the North Atlantic Oscillation (NAO). That guy, whomever he was, hit the nail on the head.

I noticed an article last week on Accu-Weather's website on this topic. The point of their article: this will be a bitterly cold month in much of the United States, and their long-range specialist, Joe Bastardi, had reversed his earlier forecast of mild conditions in January and February. Their article noted that making long-range weather predictions is still tricky business, because meteorologists are still learning how all the different variables work together.

So far, this winter has been brutal in the Carolinas. December 2010 was the second-coldest in Charlotte history, and while January so far isn't among the coldest, it's well below average -- about 5 degrees below average so far.

The reason for all this cold weather is the negative NAO. Basically, that means high pressure over Greenland has created a ripple in the atmosphere that sends arctic or polar air masses racing southward into the eastern United States. On the other side of the high, the same thing is happening in Europe.

There are signs of another big blast of arctic air moving south, toward the end of next week. We'll deal with this in our next post, but it appears as if very cold air will sweep into the eastern U.S. sometime around Jan. 22 or 23. It's possible the Carolinas will miss the worst of that, but it's a sign that the negative NAO remains locked in place, at least for now.

So I'm ready to stick a fork in the forecast for a mild winter in the Southeast, because it doesn't appear as if a trend back toward less-harsh conditions will take place anytime before the beginning of February ... if it happens then.

For the record, this will be our second straight cold winter -- and the third consecutive winter with significant snowfall.

Remember that when we have three or four straight winters with no snow.

Sunday, January 9, 2011

The likelihood of heavy snow Monday in the Carolinas is grabbing the headlines, but this storm will be a headache for a number of other reasons.

Three potential problems I see arising:

1. An ice storm across parts of the South, possibly causing thousands (or tens of thousands) of power outages.

2. Travel problems, including air travel.

3. School closing decisions, due to the timing of the snow's arrival in Charlotte.

ICE STORM WOES

Ice storm warnings are posted this morning for central and parts of southern Mississippi, and you can expect those warnings to be expanded eastward later today.

It looks as if southern Alabama (although not on the Gulf coast), south-central Georgia and parts of South Carolina's Midlands are most likely to see enough freezing rain to bring down tree limbs and power lines.

In the Charlotte region, the heaviest ice accumulations are forecast, naturally, to the south. Chester County is expected to get a little less than 1/10 of an inch of ice. Typically, anything less than 1/10 of an inch does not cause power outage problems. Normally, it takes 1/4 inch or more for tree and power line troubles.

I've seen forecasts for up to 1/2 inch of ice accumulating in parts of Georgia, Alabama and Mississippi.

We can be happy that problem is expected to remain to our south and southwest.

TRAVEL TROUBLES

Obviously, highway travel will be a precarious matter through Tuesday in the South and Southeast. This storm will affect these interstate highways: 20, 22, 24, 26, 30, 40, 55, 75, 77, and 85.

But there probably will be air travel problems, too. Some major airports, including hubs such as Atlanta, Memphis and Charlotte, figure to have delays and cancellations, especially on Monday. Some of the smaller airports also will be affected -- Little Rock, Birmingham, Jackson, Columbia, Greenville-Spartanburg.

By Monday, these cancellations could have a ripple effect that causes problems across the eastern United States, even in cities not directly impacted by the storm.

If you're planning to fly later today or Monday, have a backup plan.

SCHOOL CLOSINGS.

Pity the school superintendents who probably will have to decide on canceling classes early Monday -- before the snow ever arrives.

If the storm system continues to behave the way it's predicted to do, the decision on whether or not to close school Monday should be easy. Having 3 to 5 inches of snow fall on highways in the Carolinas means there's no school. But it's a lot easier to make that call when the snow already has arrived.

Incidentally, should this storm produce the snow and sleet that is predicted, there probably will be a lot of school closings Tuesday, too. And the delayed openings could extend into Wednesday.

Temperatures will only reach 32 to 35 degrees Tuesday, so little melting will take place. And with lows in the mid 20s Wednesday morning, the slush would re-freeze.

Saturday, January 8, 2011

Many people might look at the forecast of 4 to 6 inches of snow Monday in Charlotte as a big problem, and it will be.

But we might be getting off easy from the storm system expected to move across the South on Sunday and Monday.

A corridor farther to our south stands to get hammered by an ice storm that could knock out power to tens of thousands of customers. That area will stretch from northern Louisiana, across central Mississippi, central and southern Alabama, and southern Georgia.

Heavy snow could fall from northern Mississippi, across northern Alabama, northern Georgia and the western Carolinas.

We'll watch the development of this storm over the next few days, but it looks now (Saturday morning) as if the cities that could get the worst of the freezing rain and power outages would include Shreveport, La.; Jackson, Miss.; Montgomery, Ala.; Macon, Ga.; and possibly Columbia. Other big cities in the South -- Birmingham, Atlanta, Charlotte and Raleigh -- are more in the zone of heavy snow, rather than ice.

Friday, January 7, 2011

The computer models and meteorologists are in rare agreement that a storm system will turn the start of the work week Monday into a first-class mess in the Carolinas.

If you're of the belief that a 100 percent lock-sure forecast of snow or ice means it won't happen, suit yourself.

The rest of you might want to plan ahead for a messy Monday.

All of the computer models -- the GFS, European, and so on -- predict a low pressure system developing this weekend in the western Gulf of Mexico. That system is expected to track across the northern Gulf and then either head off the Carolinas coast and curve up the coast.

Either way, the Carolinas, especially the Piedmont, figure to be in the crosshair of the frozen precipitation. And once it falls, the frozen stuff might not disappear for a while (we'll deal with that issue later).

First, the customary caution ... the storm system responsible for this mess hasn't actually formed yet. So forecasts can change dramatically over the next few days. But the current thinking is that precipitation will move into the Charlotte area sometime shortly after midnight Sunday, probably in the form of snow.

And it will be around Monday evening or maybe early Tuesday before it ends.

Anthony Sturey, of the National Weather Service office in Greer, S.C., has produced a graphic that shows the heaviest snow and sleet accumulations in a band from Gaffney, S.C., over to western Union County. It includes the Charlotte area, and we're talking about 7 1/2 to 8 1/2 inches.

Relax! Sturey says that Armageddon-like forecast is preliminary. "these are very preliminary snow estimates," he says.

I've seen other forecasts from private meteorologists of 2 to 4 inches, with quite a bit of sleet and freezing rain on top. They think the precipitation will start as snow, then change to sleet and freezing rain by Monday afternoon.

It probably will be Sunday morning before we have a really good idea on the timing and the totals. But it's also important to mention that this storm will precede another blast of very cold air later next week.

We could be looking at single-digit morning temperatures next Friday and Saturday in the Charlotte region, with daytime highs not climbing above the mid 30s. The cold air next week will delay the melting of whatever falls Monday and will present black ice and re-freezing problems Tuesday and Wednesday mornings.

Thursday, January 6, 2011

There might not be anything pretty about the winter storm system predicted to affect the Charlotte area at the beginning of next week.

In fact, we might be dealing with the much-dreaded mixed bag of precipitation that includes ice on Monday.

A huge dome of polar air that dropped temperatures to near minus-80 degrees Fahrenheit last week in Siberia is expected to send a piece of that system crashing into Canada and the United States over the next few days.

Over the next two weeks, additional pieces of that incredibly cold air are forecast to move into the United States.

With cold air in place early next week, a low pressure system is predicted to form in the western Gulf of Mexico, move along the Gulf Coast, and then swing up the East Coast early next week. The Charlotte area would be on the cold side of that system, which means wintry precipitation.

The last time, temperatures in Charlotte were above freezing when the storm arrived, so the precipitation fell as rain for a few hours on Christmas Day, until the atmosphere cooled sufficiently and the rain changed to snow.

It's still four days from the arrival of the storm system, but meteorologists say the computer models are indicating layers of air that are above and below freezing. Specifically, some of the models (including the 6Z GFS) show a layer of warm air above a layer of freezing temperatures near the ground. That would support sleet or freezing rain.

Mike Dross, a meteorologist who used to work for Duke Energy and now puts his forecasting skills to use with the energy industry in Houston, says he sees a scenario where some parts of the Charlotte area receive 1/4 inch of ice. That's enough for power outages.

"This will probably change with future (computer model) runs," Dross says, but he adds that the freezing rain-sleet forecast is what the computers are projecting now.

And this might be just the start of a stretch of bad weather. Temperatures seem likely to remain below average for a week or more, so if any other low pressure systems develop in the Gulf, they could bring more trouble to the Charlotte area.

Tuesday, January 4, 2011

We've got the coldest air in possibly two decades headed our way next week, so let me get some unfinished business out of the way -- and then we'll start thinking about the frigid air mass headed our way.

First, let's put a wrap on 2010, and the big weather stories in the Charlotte region:

1. A non-story ... the lack of hurricanes.

The National Hurricane Center and just about every other long-range meteorologist predicted a busy year for tropical storms and hurricanes in the Atlantic basin, and they were correct. There were 19 named storms this year, compared to an average of 11.

But nearly all the storms veered away from the U.S. mainland. A few of the meteorologists who make hurricane season predictions had forecast landfall of a major storm on the Southeast coast, but a powerful high pressure system sat over our part of the country through much of July, August and September.

That kept storms from the U.S. coast. It was good news for vacationers, those who own beachfront property, and all of us who didn't have to pay $6 a gallon for gasoline (no storms affected the petroleum industry).

2. The summer heat.

There were only two days above 100 degrees, both in July, and that's not terribly out of the ordinary. But Charlotte came within an eyelash of breaking the record for 90-degree days.

There were 87 days of 90 degrees or hotter in Charlotte, barely falling short of the record of 88, set in the miserably hot summer of 1954. Summer got off to a hot start, with 18 straight 90-degree days in June, and the heat kept going through Sept. 25, when it hit 95 degrees.

On Sept. 26, the high was only 75, and that marked an end to a very hot summer.

3. Christmas snow (or Dec. 26 snow).

Whether 2010 produced a white Christmas or not is something meteorologists can argue about. The National Weather Service says official snowfall measurements are taken at 7 a.m., but there was accumulated snow in Charlotte before midnight on Christmas. So for most of us, it was a white Christmas.

While the snowfall -- and all the speculation leading up to the snow -- was something of a curiosity piece for the Charlotte area, the storm system was a serious problem farther up the East Coast, where it turned into a raging blizzard. The storm wrecked the airline flight schedule for several days and turned the Christmas holiday into a first-class mess for many travelers.

4. October 26 tornadoes.

A half-dozen tornadoes touched down in Cleveland, Catawba and Iredell counties, as a powerful low pressure system moving along a stalled cold front spread stormy weather across much of the western Carolinas.

The next day, additional severe thunderstorm activity broke out across the area, before the cold front finally sagged into South Carolina.

5. March 28 tornadoes.

A low pressure system moving across the Carolinas set off severe weather on a Sunday evening, including a tornado in Belmont and thunderstorms with damaging wind gusts in western Mecklenburg County. The same system also triggered a tornado in the northern Rowan County town of Spencer. Fortunately, there were no serious injuries.

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About this blog

Steve Lyttle says growing up in northeastern Ohio, with its foot-deep snows and summertime severe thunderstorms, fueled his interest in meteorology. He has written about weather for 10 years at The Observer. Join the discussion about weather trends and weird weather events -- whether local or around the world.